Vj. Ghosh et al., Identifying open-volume defects in doped and undoped perovskite-type LaCoO3, PbTiO3, and BaTiO3, PHYS REV B, 61(1), 2000, pp. 207-212
Dopants, vacancies, and impurity-vacancy clusters have a substantial impact
on the properties of perovskite-type metal oxides (general formula ABO(3))
. In order to determine synthesis and processing conditions that optimize t
he desirable properties of these materials a careful study of these defects
is required. It is essential to identify the defects and to map the defect
densities. Positron annihilation spectroscopy has often been used to ident
ify vacancy-type defects. Calculations of the positron lifetime and Doppler
-broadened profiles of the positron-electron annihilation radiation in undo
ped and doped LaCoO3, PbTiO3, and BaTiO3 are reported, and compared with av
ailable experimental data. The results show that these positron techniques
are excellent for studying open-volume defects, vacancy-impurity complexes,
and for identifying the sublattice occupied by the dopants.